Abstract

A new interpretation is offered for the observed reversal of contrast in the infrared absorption of nonuniformly distributed deep centers, related to EL2, in large‐diameter, liquid‐encapsulation‐grown, semi‐insulating GaAs. In the photoquenched state, having reversed contrast, the absorption originates in electrons, having been transferred from spatially clustered deep centers onto shallow centers adjacent to these clusters. Transfer is achieved by photon absorption and subsequent removal via the built‐in electric fields, generated by the clustering of the deep centers.